Animal Facts – Prairie dogs, Rats, and Bats

I’ve been reading the book “Second Nature” by Jonathan Balcombe. In it, he cites countless studies that demonstrate some fascinating characteristics about animals. I’ll periodically be posting some excerpts from the book that highlight some of the most fascinating, impressive, and surprising facts I find in the book. I hope you read the entire entry – there is nothing radical about it, just a beautifully written summary of some of the facts of life we tend to hear little about.

Today we’ll look at three animals – Prairie dogs, rats, and bats. I’ll also include a few more general excerpts from the book (one of which details a fascinating trait of chimpanzees). Enjoy!

Note: I’ve chosen not to include the sources Balcombe cites to save myself time – if you wish to know though, I’ll certainly add them.

Prairie dogs:
“Befitting their social nature, prairie dogs have developed a sophisticated system of predator detection. Their alarm calls convey specific information about an approaching foe, including species, size, shape, and even color. When hawks or humans come into view, prairie dogs run to their burrow entrances and dive inside; if the enemy is a coyote, they watch vigilantly from the burrow entrance, or if it’s a dog, they may just stand erect and watch from where they are foraging. If presented with only recordings of an alarm call in the absence of any actual predator, the rodents respond in kind.

Northern Arizona University biology professor Con Slobodchikoff, who has studied prairie dogs for over thirty years, believe that they have the most sophisticated communication system of any other mammal. To date, research has shown there to be at least twenty different basic prairie dog words describing predators, with many more variations to account for modifiers, totaling about a hundred words. They even have a specialized term for humans carrying guns.

Despite such sophisticated alarm systems, prairie dog populations, once numbering as many as five billion, have plummeted by 98 percent, mainly from extermination and habitat loss. Cattle ranchers have tried to destroy them because of perceived grazing competition (generally unsupported by data). Some hunters even take pleasure in “misting” prairie dogs – shooting the animals with hollow-point bullets that cause them to literally explode in a mist of blood. The fact that there are humans who find amusement in obliterating these harmless animals makes me wonder which species is more admirable.”

“Here’s an experiment from the University of Georgia that set out to examine whether rats have metacognition. Rats were rewarded for pressing the correct lever assigned to either a short (2 to 3.6 seconds) or a long (4.4 to 8 seconds) noise played to them. Before they could press a lever, however, they were required to poke their noses into one of two holes, one of which voided the current trial and advanced to the next one, and the other of which communicated that the rat was going to press one of the levers. Food pellets were dispensed depending on what choice the rat made: a small reward of pellets for choosing to advance to a new trial, a large reward of pellets for a correct lever choice, and no pellets for an incorrect lever choice. As you can see, just learning the experimental set-up requires some cognition on the part of the rats. The next step was even more revealing.

If the noise was obviously long (e.g., 6 seconds or more), the rats almost always elected to take the test, which usually resulted in their getting 6 pellets for a correct answer. But if the discrimination was difficult (e.g., a 4.4 second noise), the rats usually elected to void the trial, earning a smaller reward (3 pellets) in the process. In trials in which rats were not given the option to decline, they showed the lowest accuracy on the most difficult discriminations. Thus, rats appear capable of judging whether they have enough information to pass a test. They know what they know. In other words, they demonstrate metacognition.”
[I’d like to add that both myself and Balcombe heartily disapprove of the studies carried out using animals, particularly rodents – tomorrow I’ll post a passage detailing some of the mental side effects suffered by these obviously sentient, social creatures when kept in a shoe-box sized care without even a place to hide – only a water bottle and a block of processed food.]

“Echolocation is a fantastic adaptation, but it has its drawbacks. Ultrasound dissipates very fast in air, so most bats shout very loudly to detect their own echoes. How, then, does a bat’s ear detect a faint echo immediately after being bombarded with a high-intensity, potentially damaging pulse of sound that may exceed 140 decibels, well beyond the pain threshold of human hearing? The solution is as strange as it is simple: bats disable their hearing during the call phase and reactivate it during echo detection.  The fastest rates of muscle contraction are found in the ears of bats, where muscles may twitch 120 times per second to temporarily deafen the bad.”

Some other excerpts:

On pain and suffering – “In some situations, it is possible that a human’s knowing the reasons for pain – such as a necessary medical procedure – may lessen the experience of pain. British ethologist Donald Broom believes fishes may in some cases suffer more than we do, for they lack ways that we have for dealing with pain. For instance, humans can be told (or we can tell ourselves) that a pain will not last long, whereas fishes presumably are unable to do so. For American ethologist Marc Bekoff, suffering may be greater in an animal with no rich cognitive life with which to remember past events or anticipate the future. In The Unheeded Cry: Animal Consciousness, Animal Pain, and Science, American bioethicist Bernart Rollin suggests that animals with a reduced concept of time may not look forward to or anticipate the cessation of pain. ‘If they are in pain, their whole universe is pain; there is no horizon; they are their pain.'”

On instinct “Rene Descartes argued that animals were ruled by an inflexible instinct that cannot aid them in different circumstances. To this day we have a common tendency to reduce animals’ actions to mere instinct.

There is nothing ‘mere’ about instinct. Babies are instinctively drawn to movement and faces. Men are instinctively drawn to women with symmetrical faces and a big waist-to-hip ratio. Women are instinctively drawn to men with a major histocompatibility complex (a dense area of our genetic makeup that plays an important role in immunity) vastly different from their own. Instinct keeps us alive (swerving to avoid a tree), safe (avoiding precarious heights) and intact (removing your hand from a hot element). In a complex world, it would be too time-consuming (not to mention dangerous) if minds had to consciously, rationally, process all the information they are confronted with.

But what is crucial to understand about instinct is that it does not (as is so often assumed) preclude conscious experience. When you jump at a sudden noise, or you blink when something suddenly flashes before your face, you still experience and remember these events, even though your body responded involuntarily. All of the basic feelings we experience are fundamentally instinctual. We don’t intellectually learn that itchy feelings are unpleasant or that the sweetness of a blueberry is attractive, but no one would deny that a mosquito bite or a fruit smoothie are consciously experienced.”

On measuring intelligence – “We have a patronizing tendency to measure other animals’ intelligence against our own. We subject them to a sort of IQ test. Because these tests are devised by humans, they naturally contain human bias. Counting oranges in a box may reveal something of the intelligence of a human, but it sheds little light on the intelligence of a chimpanzee or a parrot. Counting fruit is not very useful to them. Recognizing edible fruits, knowing where they are in the forest and when they are due to become ripe (skills humans generally lack without specialized degrees) – these are useful bits of information to a chimp and a parrot.

Just for the record, humans are not always smarter than nonhumans. The starkest demonstration of this was discovered at Kyoto University, Japan, where a community of captive chimpanzees participated in various studies of cognition. Tetsuro Matsuzawa, who directs the program, presented the chimps with touch-sensitive computer monitors, and they soon learned to obtain small food treats by performing tasks on the monitor. One such task is to recall in sequence the numbers 1 to 9 scattered randomly on a computer screen and displayed for just one second before being replaced by white squares. Ayumu, a five-year-old chimp, excels at this. He casually but quickly points to all the white squares in sequence. Humans barely pass the test with just four or five numbers. When the British memory champiln Ben Pridmore – who can remember the order of a shuffled deck of cards in 30 seconds – competed head-to-head against Ayumu, the chimp performed three times better. When the numbers flashed for just a fifth of a second, Ayumu correctly recalled all nine digits 90 percent of the time, compared to 33 percent for Pridmore. While Ayumu is the best among his chimp peers, the average chimp scores twice as well as the average human on this short-term memory task. It appears our hairy ape cousins have a photographic memory.”

And from the introduction by J.M Coetzee: “Yet at a certain point, Balcombe suggests, principled skepticism can turn into doffed foot-dragging: here he points to a tendency among investigators – each time animals pass the tests we have set for them, they raise the bar slightly higher.”


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